Chapter 5
Mode l8500C/8500C+ Operators Manual
5-1
5.
Balance Measurement and Solutions
This chapter describes the methods and procedures for acquiring
balance measurements
and
computing/using
balance solutions
with the Model85 00C/C+ Balancer/Analyzer. Chapter 5 explains
how to take balance measurements and get solutions, under the following topics:
Section 5.1 Getting Balance Solutions: Introduction ..........................................................5-1
Section 5.2 Balance Charts..................................................................................................5-2
Section 5.3 Parameter Setup................................................................................................5-7
Section 5.4 Balance Measurement.......................................................................................5-9
Section 5.5 Solution Presentation........................................................................................5-12
Section 5.6 Additional Features...........................................................................................5-14
5.1 Getting Balance Solutions: Introduction
Balance measurement is similar to spectral data acquisition in that both operations collect spectral
frequency data from the rotor system being tested. Balance measurement, however, focuses on data
from a particular vibration signal, with the goal of providing a solution to the vibration problem. Two
types of out-of-balance conditions may be analyzed here, lateral mass imbalances and vertical track
imbalances. Lateral imbalances create vibrations that are oriented parallel to the plane of rotation.
Vertical imbalances stem from track misalignments in the rotor blades and produce vibrations that ar
perpendicular to the plane of rotation. The correct solution to both problems only requires that the
appropriate balance chart be used and that the Mode l7310 Velocimeter's cylindrical axis be oriented in
the same direction as the vibrational forces.
The solution is based on the unique characteristics of the rotor system being balanced and is presented
in terms of prescribed adjustments to the rotor hardware. These adjustments include
• Incremental addition or removal of weights at the balance points of the aircraft
• Adjustments to the sweep of the blades
• Adjustments to the trim tabs
• Adjustments to the pitch links
WARNNG: Due to the complex interaction between vertical and lateral vibrations, it is
essential that an aircraft's track be adjusted and verified before performing a lateral
balance (for more information, see Chapte r6 “Blade Track Observation”).
To Next Page
Loading...
Need help?
General
